What is the correct dosing for Vitamin D?

Vitamin D is required for the regulation of the minerals calcium and phosphorus in our body. It also plays an important role in maintaining proper bone structure. Vitamin D deficiency is more common in people who don't get enough sun light. Although people not living in sunny climates are at risk, even people living in sunny climates are also at risk, possibly because people are staying indoors more, covering up when outside, or using sunscreens to reduce skin cancer risk.The risk for vitamin D deficiency in people over 65 years of age is very high. This is because of the following facts:

They are less likely to spend time in the sun.

They have fewer receptors in their skin that convert sunlight to vitamin D.

They may not get vitamin D in their diet.

They may have trouble absorbing vitamin D even if they do get it in their diet.

They may have more trouble converting dietary vitamin D to a useful form due to kidney problems.

Dosing of Vitamin D for different health condition is recommended as below:

For Adults the recommended dose by mouth in different health condition are:

For vitamin D deficiency:

50,000 IU per week for 6 to 12 weeks can be used. However, some patients require higher doses for longer periods of time to maintain optimal blood levels of vitamin D.

For preventing osteoporosis:

400-1000 IU/day of vitamin D in a form known as cholecalciferol can be used in older adults. Usually it is taken along with 500 to 1200 mg of calcium per day. Sometimes a higher doses of 1000 to 2000 IU daily, and 0.43-1.0 mcg/day of calcitriol are recommended to use for up to 36 months.

For preventing bone loss due to use of corticosteroids:

0.25 to 1.0 mcg/day of vitamin D in forms known as calcitriol or alfacalcidol have been used for 6 to 36 months. In many cases, these forms of vitamin D are used along with calcium. Also, 50-32,000 mcg/day of vitamin D in the form of calcifediol can be used for 12 months. Finally, 1750-50,000 IU of vitamin D can be taken daily or weekly for 6 to 12 months.

For preventing cancer:

1400 to 1500 mg/day of calcium plus 1100 IU/day of vitamin D in a form known as cholecalciferol has been used for up to 7 years.

For heart failure:

800 IU/day of vitamin D in a form known as cholecalciferol can be taken alone or along with 1000 mg/day of calcium for 3 years.For bone loss caused by having too much parathyroid hormone (hyperparathyroidism): 800 IU/day of vitamin D in a form known as cholecalciferol can be used for 3 months.

Multiple sclerosis (MS):

400 IU/day of vitamin D can be used to prevent MS.

For preventing respiratory tract infections:

300 to 4000 IU of vitamin D in a form known as cholecalciferol can be used for 7 weeks to 13 months.

For preventing tooth loss in the elderly:

700 IU/day of vitamin D in a form known as cholecalciferol can be taken in combination with calcium 500 mg/day for 3 years.

Applied to Skin:

For a specific type of psoriasis called plaque psoriasis:

A form of vitamin D known as calcipotriol can be applied to the skin alone or along with corticosteroids for up to 52 weeks. Typically calcipotriol is taken at a dose of 50 mcg/gram. Specific products used in clinical studies include Daivobet and Dovobet. These products contain 50 mcg/gram of calcipotriol and 0.5 mg/gram of betamethasone dipropionate.

As a Shot:

For vitamin D deficiency:

600,000 IU of vitamin D (Arachitol, Solvay Pharma) given as a single shot into the muscle can be used.

For Children the recommended dose by mouth in different health condition are:

For preventing respiratory tract infections:

1200 IU/day of vitamin D in a form known as cholecalciferol can be given to school-aged children during the winter to prevent the flu. Also, 500 IU/day of cholecalciferol can be used to prevent worsening of asthma symptoms caused by respiratory tract infections.Most vitamin supplements contain only 400 IU (10 mcg) vitamin D.

The recommended daily allowance (RDA) varies based on age as follows:

Some organizations are recommending higher amounts of dose. The recommended dose differs by organization.

The American Academy of Pediatrics increased the recommended minimum daily intake of vitamin D to 400 IU daily for all infants and children, including adolescents. Parents should not use vitamin D liquids dosed as 400 IU/drop. Giving one dropperful or mL by mistake can deliver 10,000 IU/day.

The National Osteoporosis Foundation recommends vitamin D 400 IU to 800 IU daily for adults under age 50, and 800 IU to 1000 IU daily for older adults.

The North American Menopause Society recommends 800 IU to 1000 IU daily for all.

Guidelines from the Osteoporosis Society of Canada recommend 400-1000 IU of a specific form of vitamin D called cholecalciferol for people up to age 50, and 800-2000 IU per day for people over 50.

The Canadian Cancer Society recommends 1000 IU/day during the fall and winter for adults in Canada. This dose should be taken year round for those with a higher risk of having low vitamin D levels. This includes people who have dark skin, who usually wear clothing that covers most of their skin, and people who are older or who don't go outside often. These people have less exposure to sun.

Many experts now recommend using vitamin D supplements containing cholecalciferol in order to meet these intake levels. This seems to be more potent than another form of vitamin D called ergocalciferol.